Dot matrix display panel having a plurality of display registers

ABSTRACT

A display panel includes a plurality of dot-like display cells arrayed in rows and columns, with electrodes coupled to the cells in such a way that a plurality of rows or registers of characters can be displayed. Row and column electrodes are coupled to the rows and columns of cells to provide, in each register, a plurality of matrices of cells, each of which can be used to form a character. The panel is operated by selectively firing cells column-by-column, and, to facilitate this operation, the panel includes a column of reset cells positioned adjacent to the first column of cells in the panel and one or more keep-alive cells adjacent to the reset cells. The keep-alive cells are formed by separate anode electrodes and a common cathode electrode which is so constructed and positioned that it does not affect the other electrodes of the panel.

United States Patent Harvey et al.

l l DOT MATRIX DISPLAY PANEL HAVING A PLURALITY OF DISPLAY REGISTERS Primary Examiner-John Kominski Assistant ExaminerDarwin R. Hostetter Attorney, Agent, or FirIn-Robert A. Green; Edward G. Fiorito; Paul W. Fish OOOOOOOOOOOO 0000000000000 Jan. 28, 1975 [57 ABSTRACT A display panel includes a plurality of dot-like display cells arrayed in rows and columns, with electrodes coupled to the cells in such a way that a plurality of rows or registers of characters can be displayed. Row and column electrodes are coupled to the rows and columns of cells to provide, in each register. a plurality of matrices of cells, each of which can be used to form a character. The panel is operated by selectively firing cells column-by-column, and, to facilitate this operation, the panel includes a column of reset cells positioned adjacent to the first column of cells in the panel and one or more keep-alive cells adjacent to the reset cells. The keep-alive cells are formed by separate anode electrodes and a common cathode electrode which is so constructed and positioned that it does not affect the other electrodes of the panel.

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Pmmmmzems sum 3 or now? ow? Owe DOT MATRIX DISPLAY PANEL HAVING A PLURALITY OF DISPLAY REGISTERS BACKGROUND OF THE INVENTION Burroughs Corporation manufactures and sells a multi-register panel, known as a SELF-SCAN panel, which is a dot matrix panel and includes the structural features described above. This type of panel operates well; however, for one reason or another, a satisfactory keep-alive arrangement which can be used in mass production manufacture has not been available up to the time of this invention.

SUMMARY OF THE INVENTION Briefly, a display panel employing the invention comprises a gas-filled envelope and an assembly therein including a plurality of rows and columns of gas-filled display cells and row and column electrodes therefor. The various electrodes and the associated structural elements are interrelated and arranged to display a plurality of registers of information simultaneously. The panel includes a column of reset cells adjacent to the first column of display cells and one or more keep-alive cells adjacent to the reset cells. The electrodes of the keep-alive cells are shaped and positioned so that they provide the desired operation without interacting with any of the other electrodes of the panel.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a panel embodying the invention and illustrating the capability thereof of displaying several registers of information;

FIG. 2 is a plan view of a portion of a display panel embodying the invention;

FIG. 3 is a sectional view along the lines 3-3 in FIG. 2 but including other parts of the panel not shown in FIG. 2;

FIG. 4 is a sectional view along the lines 4-4 in FIG. 2 but including other parts of the panel not shown in FIG. 2;

FIG. 5 is a sectional view along the lines 5-5 in FIG. 2 but including other parts of the panel not shown in FIG. 2; and

FIG. 6 is a perspective view of a panel embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The principles of the invention are particularly, but not exclusively, applicable to the multi-register type of SELF-SCAN display panel sold by Burroughs Corporation as 256 character panels, one model of which is the Model No. BDS40832-PD2. These panels are also shown and described in U.S. Pat. Nos. 3,626,245 and 3,654,508. Thus, the structure and mode of operation of panels of this type are well known, and the following description provides only enough detail of the panel construction to illustrate the principles of the invention.

A display panel 10, embodying the invention and illustrated schematically in FIG. 1, is constructed to display a plurality of rows or registers 14 of characters, each made up of a plurality of dot-like cells selected from a 5 X 7, 7 X 7, or other matrix of such cells. Referring to FIG. 2, the panel 10 includes a plate of a dielectric material, such as glass or ceramic, which has a top surface 30, a bottom surface 40, an upper edge 50, a lower edge 60, a left edge 70, and a right edge 80. The plate 20 has a plurality of parallel grooves or channels 90 formed in the top surface 30 thereof. For purposes of illustration, the panel is oriented so that the grooves 90 extend horizontally across plate 20 from the left edge to the right edge 80.

As shown, the grooves include grooves D which are used to make up the dot matrix display registers, and grooves 90I which are outside or between the display registers. Single grooves 90I are shown along the upper and lower edges of the base plate, and two are shown between each group of grooves 90D which form a display register. As noted above, a dot matrix display generally utilizes arrays of 5 X 7 or 7 X 7 dots to display characters, so that each display register would include five or seven grooves 90D, as desired; however, only three are shown for convenience.

Electrodes 110, which are used as scanning anodes in one mode of operation of the panel 10, are seated in each of the three grooves 90D of each character display register, and these electrodes extend beyond the left and right edges of plate 20 and of the panel 10 so that they are accessible outside the panel. Electrodes may be individual wires set into the grooves, or they may be plated, evaporated, or otherwise formed in the grooves. The electrodes I10, if separate wires, might also be secured in the grooves 90 by means of a cement such as a fused glass frit or the like. In addition, according to the invention, an auxiliary electrode is seated in the uppermost and lowermost slots 901 and in one of each of the inter-register grooves 90I. The electrodes 120 may also be similar to electrodes 110 except that they are of minimal length and occupy only a small portion of the length of their channels adjacent to the left-hand edge of the base plate 20, as seen in FIG. 2. Electrodes 120 are thus positioned if a scanning operation, to be described, begins at the left-hand end of the panel. If electrodes 120 are wires, they may be held in place by masses of glass frit cement 93 which also serve to obstruct the right-hand portions of channels 90I, as seen in FIG. 3.

The panel 10 includes a plurality of electrodes (A. .n) which are operated as scanning cathodes and are oriented at 90 to the scanning anodes 110 to form scanning cells 210 therewith at each crossing of a cathode 160 and an anode 110 (FIG. 4). In one form of the panel 10, the electrodes 160 comprise metal strips, and each is provided with a plurality of tiny apertures 162 disposed along its length, with each aperture 162 being positioned over a groove 90 in base plate 20 and in alignment with a scanning cell 210. Each cathode 160 is aligned with a column of scanning cells 210. Apertures 162 are not required over inter-register grooves 901. The cathodes 160 are preferably identical in size and shape, for economies in manufacture, and they can be made by any suitable mass production process.

An unapertured reset cathode strip electrode 161, which may be narrower than the scanning cathodes 160, is disposed to the left of and parallel to the first scanning cathode 160A at the left-hand end of the panel and overlaying the scanning anodes 110. Each crossing of anodes 110 by cathode 160 defines a reset cell 224 (FIG. 5).

The cathodes 160 and 161 may be seated in grooves in the top surface of base plate 20 or in grooves in the bottom surface of center plate 130, if desired.

According to the invention, the panel is provided with a keep-alive cell arrangement made up of electrodes 120 as anodes and a common keep-alive cathode 163. The cathode 163 comprises an elongated metal strip disposed to the left of and parallel to reset cathode electrode 161 and seated on base plate 20. The electrode 163 is placed on the base plate in the location where the hermetic seal 200 is formed between the base plate and the other plates of the panel, to be described, so that it is embedded in the seal and is thus insulated from, and cannot interact with, the scanning anodes 110 which it crosses (FIGS. 3 and 4). The cathode 163 includes generally L-shaped arms which comprise (l horizontal portions 163H which are seated on land surfaces of the base plate 20 adjacent to the uppermost and lowermost channels 90 and (2) vertical portions 163V which overlay and are in operative relation with electrodes 120 in the uppermost and lowermost channels 90. These vertical portions 163V of the keep-alive cathode 163 and the anodes 120 form keepalive gas cells. In addition, cathode 163 is provided with L-shaped arms including horizontal portions overlaying a land or empty channel 90l and vertical portions which overlay the associated anode 120 in interregister channels 901.

it can be seen that, as thus constructed, the keepalive electrodes 120 and 163 are positioned so that they cannot adversely affect other electrodes of the panel 10.

Referring to FIG. 6, panel 10 also includes a center sheet or plate 130, of a suitable dielectric material, which is seated on the cathodes 160, 161 and 163 on base plate 20 and has a top surface 132 and a bottom surface 134. The sheet 130 is provided with a plurality of rows and columns of apertures or holes 144, each of which is aligned with a cathode aperture 162 and scanning cell 210. The apertures 144 comprise display cells in panel 10.

A plurality of electrodes 180, used as display anodes and preferably comprising wires, are seated on or in the top surface 132 of plate 130, one for each scanning anode electrode 110 in plate 90. Each electrode 180 is parallel to and aligned with an electrode 110, and each overlays a row of holes 144 in center sheet 130 and communicates with the gas in the holes and thus with a scanning cell 210.

A transparent cover or viewing plate 190, of a dielectric material such as glass, completes the panel and is seated on center plate 130. The anode electrodes 180 might be seated in slots in the bottom surface of top plate 190, or they might comprise transparent conductive strips of NESA or the like formed on the bottom surface of the top plate 190. In the completed panel 10, the three plates 20, 130, and 190 are hermetically secured together by a seal 200 formed along their adjacent edges by any suitable means such as a fused glass frit (Pyroceram) or the like. As noted above, the keepalive cathode electrode 163 is embedded in the seal, and the panel sealing cement fills the channels 90 beneath it and thus insulates it from scanning anodes 110, as illustrated in FIGS. 3 and 4.

The panel 10 includes any suitable ionizable gas such as neon, argon, xenon, etc., singly or in combination, with a vapor of a metal such as mercury usually included in the gas to minimize cathode sputtering. The gas is introduced into the panel in any suitable manner,

for example, by means of a tubulation 203 secured to base plate 20 (FIG. 4).

The operation of SELF-SCAN panels is now well known; therefore, the operation of panel 10 will not be described in detail. it is sufficient to note that the keepalive cathode 163 and the keep-alive anodes are connected to a suitable power supply. and the keep-alive cells are maintained constantly ON and ionized and generating excited particles. At the beginning of a scanning cycle, the reset cells 224 are energized by connection of the reset cathodes 161 and all of the scanning anodes 110 to external circuit drivers. The reset cells turn on and are ionized with the aid of excited particles generated by the keep-alive cells, and, as is well known. excited particles now generated by the reset cells facilitate the ionization of the first column of scanning cells. The columns of scanning cells are ionized sequentially, and, simultaneously, information signals are applied to the display anodes to transfer glow into selected display cells from the assocaited scanning cells. This scanning and display operation is carried out continually and sequentially at such a rate that a changeable but apparently stationary message is embodied in the selected display cells which are turned on.

it is to be understood that panel 10 may also be manufactured without inter-register channels l, in which case, the upper and lower keep-alive cell arrangement would be employed.

What is claimed is:

1. A display panel comprising a gas-filled envelope including a bottom plate. a center plate, and a top plate, all being of dielectric material and hermetically sealed together by a sealing material,

said bottom plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge. and a lower edge,

said bottom plate also having a plurality of parallel slots extending into said plate from said top surface and extending along the entire length of said plate.

first anode electrodes seated in several groups of said slots and extending along the entire length thereof and beyond both ends thereof, said slots comprising portions of display registers in said panel.

said center plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge,

a plurality of cathode electrodes disposed between said bottom plate and said center plate and oriented at an angle to said first anode electrodes. each cathode electrode crossing each first anode electrode, each crossing defining a first cell which can be fired by potentials applied to the two electrodes at the crossing, there thus being an array of rows and columns of said first cells including a first column, a last column and intermediate columns,

a column of reset cells adjacent to said first column of said first cells,

at least one keep-alive cell positioned adjacent to said column of reset cells,

said keep-alive cell comprising a keep-alive anode electrode seated in one of said slots in said bottom plate and a keep-alive cathode electrode comprising a metal strip portion which is shielded from said first anode electrodes and said cathode electrodes. said keep-alive cathode including a projecting tab which extends from said strip portion and overlays said keep-alive anode and is in electrical operating relationship only with said keep-alive anode,

a plurality of holes formed in said center plate and arrayed in rows and columns, each column of holes being aligned with one of said second electrodes, and

a plurality of second anode electrodes aligned with the rows of said holes and disposed between said top plate and said center plate, each such second anode electrode also being aligned with one of said first electrodes.

2. The panel defined in claim 1 wherein said projecting tab of said keep-alive cathode is generally L-shaped and includes a first portion overlaying the top surface of said base plate and a second portion which projects toward and overlays said keep-alive anode.

3. The panel defined in claim 1 wherein said metal strip portion of said keep-alive cathode is embedded in said sealing material and is thus shielded from other electrodes in said panel.

4. A display panel comprising a gas-filled envelope including a bottom plate, a center plate, and a top plate, all being of dielectric material and hermetically sealed together by a sealing material,

said bottom plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge,

said bottom plate also having a plurality of first parallel identical slots extending into said plate from said top surface and extending along the entire length of said plate,

first anode electrodes seated in several groups of said first slots and extending along the entire length thereof and beyond both ends thereof, said groups of first slots comprising portions of display registers in said panel,

each of said several groups of said first slots being separated by at least one inter-register slot which does not contain one of said first electrodes in it,

said center plate having a top surface, a bottom surface, a left edge, a rightedge, an upper edge, and a lower edge,

a plurality of cathode electrodes disposed between said bottom plate and said center plate and oriented at an angle to said first anode electrodes, each cathode electrode crossing each first anode electrode, each crossing defining a first cell which can be fired by potentials applied to the two electrodes at the crossing, there thus being an array of rows and columns of said first cells including a first column, a last column and intermediate columns.

a column of reset cells adjacent to said first column of said first cells,

at least one keep-alive cell positioned adjacent to said column of reset cells,

said keep-alive cell comprising a keep-alive anode electrode seated in one of said inter-register slots in said bottom plate and a keep-alive cathode electrode comprising a metal strip portion which is shielded from said first anode electrodes and said cathode electrodes, said keep-alive cathode including a projecting tab which extends from said strip portion and overlays said keep-alive anode and is in electrical operating relationship only with said keep-alive anode,

a plurality of holes formed in said center plate and arrayed in rows and columns, each column of holes being aligned with one of said second electrodes, and

a plurality of second anode electrodes aligned with the rows of said holes and disposed between said top plate and said center plate, each such second anode electrode also being aligned with one of said first electrodes.

5. The panel defined in claim 4 wherein said projecting tab of said keep-alive cathode is generally L-shaped and includes a first portion overlaying one of said slots which does not contain an electrode, and a second portion which projects towards and overlays said keepalive anode.

6. The panel defined in claim 4 wherein said metal strip portion of said keep-alive cathode is embedded in said sealing material and is thus shielded from other electrodes in said panel.

7. The panel defined in claim 4 and including an inter-register slot between each of said groups of slots, and a keep-alive anode in each of said inter-register 

1. A display panel comprising a gas-filled envelope including a bottom plate, a center plate, and a top plate, all being of dielectric material and hermetically sealed together by a sealing material, said bottom plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge, said bottom plate also having a plurality of parallel slots extending into said plate from said top surface and extending along the entire length of said plate, first anode electrodes seated in several groups of said slots and extending along the entire length thereof and beyond both ends thereof, said slots comprising portions of display registers in said panel, said center plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge, a plurality of cathode electrodes disposed between said bottom plate and said center plate and oriented at an angle to said first anode electrodes, each cathode electrode crossing each first anode electrode, each crossing defining a first cell which can be fired by potentials applied to the two electrodes at the crossing, there thus being an array of rows and columns of said first cells including a first column, a last column and intermediate columns, a column of reset cells adjacent to said first column of said first cells, at least one keep-alive cell positioned adjacent to said column of reset cells, said keep-alive cell comprising a keep-alive anode electrode seated in one of said slots in said bottom plate and a keepalive cathode electrode comprising a metal strip portion which is shielded from said first anode electrodes and said cathode electrodes, said keep-alive cathode including a projecting tab which extends from said strip portion and overlays said keepalive anode and is in electrical operating relationship only with said keep-alive anode, a plurality of holes formed in said center plate and arrayed in rows and columns, each column of holes being aligned with one of said second electrodes, and a plurality of second anode electrodes aligned with the rows of said holes and disposed between said top plate and said center plate, each such second anode electrode also being aligned with one of said first electrodes.
 2. The panel defined in claim 1 wherein said projecting tab of said keep-alive cathode is generally L-shaped and includes a first portion overlaying the top surface of said base plate and a second portion which projects toward and overlays said keep-alive anode.
 3. The panel defined in claim 1 wherein said metal strip portion of said keep-alive cathode is embedded in said sealing material and is thus shielded from other electrodes in said panel.
 4. A display panel comprising a gas-filled envelope including a bottom plate, a center plate, and a top plate, all being of dielectric material and hermetically sealed together by a sealing material, said bottom plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge, said bottom plate also having a plurality of first parallel identical slots extending into said plate from said top surface and extending along the entire leNgth of said plate, first anode electrodes seated in several groups of said first slots and extending along the entire length thereof and beyond both ends thereof, said groups of first slots comprising portions of display registers in said panel, each of said several groups of said first slots being separated by at least one inter-register slot which does not contain one of said first electrodes in it, said center plate having a top surface, a bottom surface, a left edge, a right edge, an upper edge, and a lower edge, a plurality of cathode electrodes disposed between said bottom plate and said center plate and oriented at an angle to said first anode electrodes, each cathode electrode crossing each first anode electrode, each crossing defining a first cell which can be fired by potentials applied to the two electrodes at the crossing, there thus being an array of rows and columns of said first cells including a first column, a last column and intermediate columns, a column of reset cells adjacent to said first column of said first cells, at least one keep-alive cell positioned adjacent to said column of reset cells, said keep-alive cell comprising a keep-alive anode electrode seated in one of said inter-register slots in said bottom plate and a keep-alive cathode electrode comprising a metal strip portion which is shielded from said first anode electrodes and said cathode electrodes, said keep-alive cathode including a projecting tab which extends from said strip portion and overlays said keep-alive anode and is in electrical operating relationship only with said keep-alive anode, a plurality of holes formed in said center plate and arrayed in rows and columns, each column of holes being aligned with one of said second electrodes, and a plurality of second anode electrodes aligned with the rows of said holes and disposed between said top plate and said center plate, each such second anode electrode also being aligned with one of said first electrodes.
 5. The panel defined in claim 4 wherein said projecting tab of said keep-alive cathode is generally L-shaped and includes a first portion overlaying one of said slots which does not contain an electrode, and a second portion which projects towards and overlays said keep-alive anode.
 6. The panel defined in claim 4 wherein said metal strip portion of said keep-alive cathode is embedded in said sealing material and is thus shielded from other electrodes in said panel.
 7. The panel defined in claim 4 and including an inter-register slot between each of said groups of slots, and a keep-alive anode in each of said inter-register slots. 